Method of manufacturing tubular bodies.



'VU @444 Z attolzwz ux METHOD OF MANUFACTURING TUBULAR BODIES.

(Application filed July 1, 1901.)

QNo Model.)

No. 682,360. Patented Sept. l0, l90l. H. R. KEITHLEY.

METHOD OF MANUFACTURING TUBULAR BODIES.

(Application filed July 1, 1901.)

2 Sheets-Sheet 2.

(No Model.)

IO I

UNITED STATES PATENT EricE.

HERBERT R. KEITHLEY, OF WILSON, NEW YORK.

METHOD OF MANUFACTURING TUBULAR BODIES.

SPECIFICATION forming part of Letters Patent No. 682,360, datedSeptember 10, 1901.

Application filed July 1, 1901.

T0 60% whom it may concern:

Be it known that I, HERBERT R. KEITHLEY, of Wilson, in the county ofNiagara and State of New York, have invented certain new and usefulImprovements in Methods of Manufacturing Tubular Bodies; and I do herebydeclare the following to be a full, clear, and

exact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same.

My invention relates to the manufacture of seamless tubular bodies fromsolid bodies of metal.

In the present state of the art there are two principal methods orprocesses of manufacturing seamless tubular bodies. One of theseprocesses consists in confining a solid piece 'of hot metal in asuitable chamber and forcing a punch into or through the mass to formthe tube. In the other process referred to the tubular blank is producedon a man- 'drel between rolls having differential rotation at highvelocity and is called the disk rolling or piercing process. Theprincipal difficulty encountered in the first named process is toproduce a tubular blank of the length required to work into the commercially-finished form, which blank shall have a perfectly-centeredhole or bore, so that the walls are of uniform thickness. Commercialtubing is now made in lengths of about twenty feet, and this requiresthat the original seamless tubular blank be approximately three feetlong. To punch a hole of the required size through a solid mass of metalof such a length(three feet) and to preserve the exact alinement of thepunch under the heavy pressures required to penetrate the metal has beenfound to be so difficult and uncertain that this process has beensuperseded by the disk rolling or piercing process above referred to.This latter process requires the use of a highgrade open-hearth steel,which is very expensive. This is necessary because it has been foundthat the use of the ordinary grade of open-hearth steel or Bessemer willnot produce satisfactory results. It has also been found that even whenhigh-grade steel is employed in this process the efiect of the excessiveworking and manipulation of the metal Serial No. 66,667. (No model.)

mass has been such that the product cannot be machined and prepared forvarious mechanical uses with satisfactory results. This disk rolling orpiercing process has the disadvantage of requiring very expensivemachinery which in operation requires constant and careful attention inorder that the adjustments of the various parts throughout may beproperly maintained; otherwise the product will be defective.

The object of my invention is to produce from the ordinary grades ofsteel a seamless tubular blank which will not be open to the objectionsabove pointed out and to accomplish this result by a means and processefficient, economical, and reliable.

In the the accompanying drawings I have shown one form of machine bywhich my process may be practiced.

The first step in my process comprises heating a solid body of metal;second, punching said body by a punch or mandrel while it is held in asuitable chamber to thereby form a short heavy tubular body, and,finally, by pressure applied direct to the short heavy tubular body itis forced through a tubular pass of less diameter than said tubular bodyand contracted. diametrically, so that the metal being displaced iscaused to flow longitudinally and forward beyond the point of the punchor mandrel, thus forming a tubular body of greater length than saidpunch or mandrel. During the process a superior longitudinal fibrousstructure isimparted to the tube.

In the drawings, Figure l is a longitudinal sectional view of a machineby the use of which my process may be practiced. Figs. 2, 3, and 4 aresimilar views, the parts being shown in different positions for thepurpose of illustrating the successive steps of the process.

1 is a plunger or rod carried by preference by a piston 2, movable in acylinder 3.

4 is a punch or mandrel.

In the forward end of the cylinder 3 there is a passage of a sizecorresponding to the size of the plunger or piston 1. This passage willhereinafter be termed the blank-chamher. 5 is a tubular abutment, thepassage through which is of less diameter than said blank-chamber but oflarger diameter than said punch. This tubular abutment is movable bymeans of a piston 6, in turn movable within a cylinder 7.

Sis a piston-rod of a size corresponding to the bore of thetubularabutment 5 and movable therein. This piston 8 may be moved by a piston9, in turn movable in a cylinder 10.

The casing or casings forming the pistoncylinders are connected in anydesirable wayfor example, by rods or bolts 11 11. The pistons may beoperated hydraulically or by any other suitable mechanical means.

The preferred form and means by which the plunger 1, the punch 4-, thetubular abutment '5, and the piston 8 are operated is shown in thedrawings, although it is obvious the same may be modified in form andarrangement. I

In operation the first step of the process comprises heating a solidblank and then inserting said blank into the blank-chamber, so that itwill occupy the position, for example, substantially as shown in Fig. 1.The piston 8 and the tubular abutment 5 are so positioned that theyclose the otherwise open end of the said blank-chamber-for example, asshown in Fig. 1. The punchet is then advanced from the position shown inFig. 1 to the position shown in Fig. 2, thereby punching said solidblank and forming the short heavy tubular body shown in Fig. 2. Thepiston 8 is then retracted, say, to the position shown in Fig. 8, andthe next step in the process comprises forcing the plunger from theposition shown in Fig. 2 to the position shown in Fig. 3, during whichoperation the metal is displaced and caused to flow through thecontracted passage between the Wall of the tubular abutment and thepunch, which together form what may be termed a tubular die. Thismovement of the metal causes it by displacement to move longitudinallyand forwardly beyond the point of the punch, thereby forming anelongated tubular body sub-v stantially of the completed form shown inFigs. 3 and 4. The plunger 1 and punch 4 may then be retracted. The tubemay then be removed by retracting the tubular abutment 5. In Fig. 4 theabutment 5 is retracted; but the tube is shown as being slightly inengagement therewith. It may be entirely freed therefrom, however, byslightly adattest vancing the piston 8 or retracting the tubularabutment still further.

From the foregoing it will be seen that by this process and by theemployment of a suitable means a perfectly-centered hole will be formedin a metal blank, so that the walls around the same will be of uniformthickness. This is possible by reason of the fact that the punch ormandrel employed in this process is substantially shorter than thelength of the tubular body finally produced. By the use of the shortpunch or mandrel the said device when performing the function of a punchwill successfully resist deflection from true alinement notwithstandingthe great pressure required to penetrate the solid mass of heated metal.When the point of the punch has entered the pass of reduced diameter, itthen begins to perform the function of a mandrel coacting with the wallof said pass, so that said parts act upon the metal as a die. Underthese conditions the pressure of the metal against the punch, which nowacts as a mandrel, will not deflect the same from true alinement sincethe resistance against the end of said member ceases, due to the factthat the metal by displacement is caused to move or flow longitudinallyand forwardly beyond the point of the punch.

What I claim is A process for manufacturing a seamless tubular iron orsteel body from a solid body in a continuous operation, said processcom= prising heating a solid iron or steel blank, then punching saidblank while the same is confined at its sides, thereby forming a short,tubular body, then forcing said tubular body through a tubular die ofless diameter than the said short, tubular body, thereby contractingsaid body diametrically so that the metal is caused by displacement toflow longitudinally and forwardly beyond the point of the punch ormandrel, thereby elongating said body and forming in the finishedproduct longitudinal fiber.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

HERBERT R. KEITHLEY.

Witnesses:

R. O. MITCHELL, E. F. OAVERLY.

